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如何以数组形式访问参数 powershell

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如何以数组形式访问参数 powershell

我不明白为什么我无法访问 param 的值。

cls


function __main{
    param(
          [string]$coche,  
          [string]$casa
        )

    foreach($i in $param){

        write-host "$i"
        
    }
}

__main coche casa

输出：

PS C:\>

预期输出：

coche
casa

我知道可以用 $car 或 $house 逐个调用它们，但事实并非如此，因为我应该创建一个数组，而我不想这样：

cls


function __main{
    param(
          [string]$coche,  
          [string]$casa
        )

$arr = @($coche,$casa)

    foreach($i in $arr){

        write-host "$i"
      
        
    }
}

__main coche casa

答案1

延伸我的评论。

您也可以使用此方法检查代码正在执行的操作（以及更多操作，例如参数绑定）。

参见：Trace-Command

 function __main{
    param(
          [string]$coche,  
          [string]$casa
        )

    foreach($i in $param){

        write-host "$i"
        
    }
}

__main coche casa

Trace-Command -Name metadata,parameterbinding,cmdlet -Expression {__main coche casa} -PSHost
# Results
<#
The variable '$param' cannot be retrieved because it has not been set.
At line:7 char:19
+     foreach($i in $param){
+                   ~~~~~~
    + CategoryInfo          : InvalidOperation: (param:String) [], RuntimeException
    + FullyQualifiedErrorId : VariableIsUndefined
 
DEBUG: ParameterBinding Information: 0 : BIND arg [coche] to parameter [coche]
DEBUG: ParameterBinding Information: 0 :     Executing DATA GENERATION metadata: [System.Management.Automation.ArgumentTypeConverterAttribute]
DEBUG: ParameterBinding Information: 0 :         result returned from DATA GENERATION: coche
DEBUG: ParameterBinding Information: 0 :     BIND arg [coche] to param [coche] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND arg [casa] to parameter [casa]
DEBUG: ParameterBinding Information: 0 :     Executing DATA GENERATION metadata: [System.Management.Automation.ArgumentTypeConverterAttribute]
DEBUG: ParameterBinding Information: 0 :         result returned from DATA GENERATION: casa
DEBUG: ParameterBinding Information: 0 :     BIND arg [casa] to param [casa] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND PIPELINE object to parameters: [Out-Default]
DEBUG: ParameterBinding Information: 0 :     PIPELINE object TYPE = [System.Management.Automation.ErrorRecord]
DEBUG: ParameterBinding Information: 0 :     RESTORING pipeline parameter's original values
DEBUG: ParameterBinding Information: 0 :     Parameter [InputObject] PIPELINE INPUT ValueFromPipeline NO COERCION
DEBUG: ParameterBinding Information: 0 :     BIND arg [The variable '$param' cannot be retrieved because it has not been set.] to parameter [InputObject]
DEBUG: ParameterBinding Information: 0 :         BIND arg [The variable '$param' cannot be retrieved because it has not been set.] to param [InputObject] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Out-Default]
DEBUG: ParameterBinding Information: 0 : BIND PIPELINE object to parameters: [Out-LineOutput]
DEBUG: ParameterBinding Information: 0 :     PIPELINE object TYPE = [System.Management.Automation.ErrorRecord]
DEBUG: ParameterBinding Information: 0 :     RESTORING pipeline parameter's original values
DEBUG: ParameterBinding Information: 0 :     Parameter [InputObject] PIPELINE INPUT ValueFromPipeline NO COERCION
DEBUG: ParameterBinding Information: 0 :     BIND arg [The variable '$param' cannot be retrieved because it has not been set.] to parameter [InputObject]
DEBUG: ParameterBinding Information: 0 :         BIND arg [The variable '$param' cannot be retrieved because it has not been set.] to param [InputObject] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [out-lineoutput]
DEBUG: ParameterBinding Information: 0 : BIND PIPELINE object to parameters: [Format-Default]
DEBUG: ParameterBinding Information: 0 :     PIPELINE object TYPE = [System.Management.Automation.ErrorRecord]
DEBUG: ParameterBinding Information: 0 :     RESTORING pipeline parameter's original values
DEBUG: ParameterBinding Information: 0 :     Parameter [InputObject] PIPELINE INPUT ValueFromPipeline NO COERCION
DEBUG: ParameterBinding Information: 0 :     BIND arg [The variable '$param' cannot be retrieved because it has not been set.] to parameter [InputObject]
DEBUG: ParameterBinding Information: 0 :         BIND arg [The variable '$param' cannot be retrieved because it has not been set.] to param [InputObject] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [format-default]
DEBUG: ParameterBinding Information: 0 : BIND NAMED cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 :     BIND arg [1] to parameter [Version]
DEBUG: ParameterBinding Information: 0 :         Executing DATA GENERATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ArgumentToVersionTransformat
ionAttribute]
DEBUG: ParameterBinding Information: 0 :             result returned from DATA GENERATION: 1.0
DEBUG: ParameterBinding Information: 0 :         COERCE arg to [System.Version]
DEBUG: ParameterBinding Information: 0 :             Parameter and arg types the same, no coercion is needed.
DEBUG: ParameterBinding Information: 0 :         Executing VALIDATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ValidateVersionAttribute]
DEBUG: ParameterBinding Information: 0 :         BIND arg [1.0] to param [Version] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND POSITIONAL cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : CALLING BeginProcessing
DEBUG: ParameterBinding Information: 0 : CALLING EndProcessing
DEBUG: ParameterBinding Information: 0 : BIND NAMED cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 :     BIND arg [1] to parameter [Version]
DEBUG: ParameterBinding Information: 0 :         Executing DATA GENERATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ArgumentToVersionTransformat
ionAttribute]
DEBUG: ParameterBinding Information: 0 :             result returned from DATA GENERATION: 1.0
DEBUG: ParameterBinding Information: 0 :         COERCE arg to [System.Version]
DEBUG: ParameterBinding Information: 0 :             Parameter and arg types the same, no coercion is needed.
DEBUG: ParameterBinding Information: 0 :         Executing VALIDATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ValidateVersionAttribute]
DEBUG: ParameterBinding Information: 0 :         BIND arg [1.0] to param [Version] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND POSITIONAL cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : CALLING BeginProcessing
DEBUG: ParameterBinding Information: 0 : CALLING EndProcessing
DEBUG: ParameterBinding Information: 0 : BIND NAMED cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 :     BIND arg [1] to parameter [Version]
DEBUG: ParameterBinding Information: 0 :         Executing DATA GENERATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ArgumentToVersionTransformat
ionAttribute]
DEBUG: ParameterBinding Information: 0 :             result returned from DATA GENERATION: 1.0
DEBUG: ParameterBinding Information: 0 :         COERCE arg to [System.Version]
DEBUG: ParameterBinding Information: 0 :             Parameter and arg types the same, no coercion is needed.
DEBUG: ParameterBinding Information: 0 :         Executing VALIDATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ValidateVersionAttribute]
DEBUG: ParameterBinding Information: 0 :         BIND arg [1.0] to param [Version] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND POSITIONAL cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : CALLING BeginProcessing
DEBUG: ParameterBinding Information: 0 : CALLING EndProcessing
DEBUG: ParameterBinding Information: 0 : BIND NAMED cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 :     BIND arg [1] to parameter [Version]
DEBUG: ParameterBinding Information: 0 :         Executing DATA GENERATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ArgumentToVersionTransformat
ionAttribute]
DEBUG: ParameterBinding Information: 0 :             result returned from DATA GENERATION: 1.0
DEBUG: ParameterBinding Information: 0 :         COERCE arg to [System.Version]
DEBUG: ParameterBinding Information: 0 :             Parameter and arg types the same, no coercion is needed.
DEBUG: ParameterBinding Information: 0 :         Executing VALIDATION metadata: [Microsoft.PowerShell.Commands.SetStrictModeCommand+ValidateVersionAttribute]
DEBUG: ParameterBinding Information: 0 :         BIND arg [1.0] to param [Version] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND POSITIONAL cmd line args [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Set-StrictMode]
DEBUG: ParameterBinding Information: 0 : CALLING BeginProcessing
DEBUG: ParameterBinding Information: 0 : CALLING EndProcessing
The variable '$param' cannot be retrieved because it has not been set.
At line:7 char:19
+     foreach($i in $param){
+                   ~~~~~~
    + CategoryInfo          : InvalidOperation: (param:String) [], RuntimeException
    + FullyQualifiedErrorId : VariableIsUndefined
 
#>

 function __main{
    param(
          [string]$coche,  
          [string]$casa
        )

$arr = @($coche,$casa)

    foreach($i in $arr){

        write-host "$i"
      
        
    }
}

__main coche casa

Trace-Command -Name metadata,parameterbinding,cmdlet -Expression {__main coche casa} -PSHost

# Results
<#
coche
casa
DEBUG: ParameterBinding Information: 0 : BIND arg [coche] to parameter [coche]
DEBUG: ParameterBinding Information: 0 :     Executing DATA GENERATION metadata: [System.Management.Automation.ArgumentTypeConverterAttribute]
DEBUG: ParameterBinding Information: 0 :         result returned from DATA GENERATION: coche
DEBUG: ParameterBinding Information: 0 :     BIND arg [coche] to param [coche] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND arg [casa] to parameter [casa]
DEBUG: ParameterBinding Information: 0 :     Executing DATA GENERATION metadata: [System.Management.Automation.ArgumentTypeConverterAttribute]
DEBUG: ParameterBinding Information: 0 :         result returned from DATA GENERATION: casa
DEBUG: ParameterBinding Information: 0 :     BIND arg [casa] to param [casa] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : BIND NAMED cmd line args [Write-Host]
DEBUG: ParameterBinding Information: 0 : BIND POSITIONAL cmd line args [Write-Host]
DEBUG: ParameterBinding Information: 0 : BIND REMAININGARGUMENTS cmd line args to param: [Object]
DEBUG: ParameterBinding Information: 0 :     BIND arg [System.Collections.Generic.List`1[System.Object]] to parameter [Object]
DEBUG: ParameterBinding Information: 0 :         COERCE arg to [System.Object]
DEBUG: ParameterBinding Information: 0 :             Parameter and arg types the same, no coercion is needed.
DEBUG: ParameterBinding Information: 0 :         BIND arg [System.Collections.Generic.List`1[System.Object]] to param [Object] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Write-Host]
DEBUG: ParameterBinding Information: 0 : CALLING BeginProcessing
coche
DEBUG: ParameterBinding Information: 0 : CALLING EndProcessing
DEBUG: ParameterBinding Information: 0 : BIND NAMED cmd line args [Write-Host]
DEBUG: ParameterBinding Information: 0 : BIND POSITIONAL cmd line args [Write-Host]
DEBUG: ParameterBinding Information: 0 : BIND REMAININGARGUMENTS cmd line args to param: [Object]
DEBUG: ParameterBinding Information: 0 :     BIND arg [System.Collections.Generic.List`1[System.Object]] to parameter [Object]
DEBUG: ParameterBinding Information: 0 :         COERCE arg to [System.Object]
DEBUG: ParameterBinding Information: 0 :             Parameter and arg types the same, no coercion is needed.
DEBUG: ParameterBinding Information: 0 :         BIND arg [System.Collections.Generic.List`1[System.Object]] to param [Object] SUCCESSFUL
DEBUG: ParameterBinding Information: 0 : MANDATORY PARAMETER CHECK on cmdlet [Write-Host]
DEBUG: ParameterBinding Information: 0 : CALLING BeginProcessing
casa
DEBUG: ParameterBinding Information: 0 : CALLING EndProcessing
#>

如果您只是想查看命令中的参数，请尝试以下操作：

(Get-Command -Name __main).Parameters
(Get-Command -Name __main).Parameters.Keys

参数当然是用来为它们提供处理的值，并用于自动完成功能。编写一个函数来尝试输出其参数并不是真正的事情。因此有上述内容。

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